Seminar on :Broadband Over Power Line

Kaushik PatnaikElectronics and Telecommunication Engineering sec ‘B’0711014017 (BC)13/08/2010

Talk flow :• 1. Introduction• 2. Existing Power grid • 3. Altered Power grid hierarchy• 4 . BPL architecture • 5. Defining Network layers• 6. Challenges and solution• 7. Potential benefits• 8. IEEE standards• 9. Network profiles• 10. Conclusion

Existing Power Grid

Power grid hierarchy

ALTERED POWER GRID

Altered power grid :

• Why MV lines ? -EHV,HV are too noisy -MV are less branched , Hence long distance end- to end connection possible -weaker signal attenuation , low noise

• Couplers could be Inductive or capacitive

• Why inductive couplers , despite being lossy ? -No physical connection -safe to install on energized power line

• Why By-pass transformer ? - Distribution tr. meant to pass 50-60Hz signal , acts as OC for high

frequency Broadband signal(2-32 MHz)- Signal gets distorted permanenently ,beyond usability- Must have In-built repeating functionality

Different BPL architectures :

Architecture Overview• Option 1.(wireless) Transformer avoided - OFDM used for distributing

data - Wifi exchange point at user-end and the MV-line transmitter using IEEE 802.11 standard

• Option 2.(wired) Transformer avoided – OFDM employed – BPL

extractor routes data from MV to LV and user

• Option 3(wired) By-pass transformer with LV,MV coupler and

repeater

Injection via Back-haul network

- Bridging Broadband to Power lines

- Bidirectional device meant for converting data formats aggregating stream via Network Operating Center(NOC) ,helps allocating BW for proper injection of signal into MV line.

- Employs Network management system(NMS) software for control , monitoring of power network and application server (e.g- VoIP , Internet)

Network layer implementation• Physical Layer

- Sub layer where data is physically moved across electrical/mech interface

- Houses the programmed hardware and functions

- CDMA : Preferred for higher bit rate- OFDM : specially fit for noisy medium (power line), : efficient BW utilization : more fault tolerant than CDMA : frequency selective capacity : frequency suppressing feature so as to suppress the HF Short wave radio

• MAC(Medium access control) Layer- forms a sublayer of DataLink Layer responsible for moving data packets b/w NIC in a shared medium.- MAC protocol ensures signal from multiple user modems

in the shared medium don’t collide. - WHY CSMA/CA protocol ?- For anti-collision among signal sent by modems.- To provide QoS for high bandwidth application

(e.g video streaming)- For good performance guarantee

• Implementation challenges and solution :

1. Noise due to time-varying nature of load(L V)2. Unshielded , untwisted line could act as antenna

raising interference issue. < sol. corridor system>3. Unauthorized interception of sensitive data via

shared medium. < Protocol >4. More end-users , lesser through put 5. Channel attenuation 1dB/km , as high as 40 dB/km in

10kHz- 20 MHz .

s 2 power line as

antenna

RADIATION LIMITS

Interference measurement set up

Potential benefits :1. Service providers – No need for new Tx line. No need for site acquisition, permitting, licensing or purchasing spectrum.

2. Electric utilities – -Smart grid for system monitoring, fault detection analysis, asset

mgmt utilization, SCADA -new source of revenue from existing infrastructure

3. End users – -only viable option in rural area with power line -Turns every plug into Broadband communication access point

Profile of Internet access

Profile contd…

IEEE standards for BPL

• IEEE P1675 “standard for BPL hardware” develops standards for hardware installation

and safety. • IEEE P1775 “standard for electromagnetic compatibility(EMC), test and measurement ” • IEEE P1901 “standard for BPL MAC and physical sub-layer for high speed >100mbps”

Conclusion :• Only 21% of earths population has the access to internet

connection via DSL or dial up. Hence, It could provide an alternate mean .

• Tremendous benefits to remote rural area with as 63.2 % of rural

areas are electrified.

• Quick ,low cost broadband along with VoIP , PSTN using existing power lines.

• Single plug acquires both electricity and broadband.

• Connectivity is now productivity.

Reference :• “Howstuffworks.com”

• “Bechtel Telecommunications Technical Journal, January 2007 • Volume 5, Number 1 ”

• “Home Plug Powerline Alliance (http://www.homeplug.org/en/index.asp).”

• “Power Line Communications: An Overview,IEEE Conference Proceedings for AFRICON 1996

• “Opportunities in Broadband over Power Line,”Report by The Shpigler Group and UTC Research

THANK YOU